What does a Skill unlock at its various levels?

Doomsday Operation

Level 1
Bosonic Field GeneratorModule
'Jormungandr' Explosive ReaperModule
'Holy Destiny' Electromagnetic LanceModule
'Cold Wind' Kinetic ReaperModule
'Oblivion' Kinetic DoomsdayModule
'Phalarica' Thermal LanceModule
'Gjallarhorn' Explosive DoomsdayModule
Gravitational Transportation Field OscillatorModule
'Divine Harvest' Electromagnetic ReaperModule
'Guillotine' Thermal ReaperModule
'Aurora Ominae' Thermal DoomsdayModule
'Geiravor' Explosive LanceModule
'Judgment' Electromagnetic DoomsdayModule
'Iron Pike' Kinetic LanceModule
Level 2
Doomsday Rapid FiringSkill